Process of making iron, steel, or steel alloys



` J. A. WILLIAMS PROCESS 0F MAKING IRON, STEEL/.0R STEEL ALLoYs Filed Deo. 6, 1920 /Ewelo PatentedO pr. 24, 1923.

Unirse STATES 1,453,057 PATENT oFFicE.

v JOSEPH A. WILLIAMS, OF CLEVELAND, OHIO.

PROCESS OF -MAKING IRON', STEEL, OB STEEL ALLOYS.

' To all whom it may concern.'

]ecting any ofthe materials employed to a melting or smelting process.

The principal object of the invention is to provide a process which results in a very high grade product such, for example, as is desired for the production of certain accurately formed parts heretofore made by casting and subsequent machining, and such as is desired for the production of tools, dies` cutlery, etc.

More particularly theinvention aims to provide a process by which a product is obtained which is entirely or substantially entirely free of impurities, and iny s`o far as the production of steely or steel alloys is concerned, to produce a product having a known or absolutely definite carbon content, or a definite content of the alloying metal or metals; also a product whic is homogeneous chemically and physically, and one free of so-called segregations, blowholes and the like.

The invention may be briefly summarized as consisting in certain novel steps of the improved method which will bedescribed in the specification and set forth in the appended claims.

Though the invention is not confined to any particular form 0r construction of apparatus, in the drawing I have shown conventionally in vertical section, an apparatus which may be used to advantage in carryi110r out the principal steps of the process.

n carrying out my improved process I prefer to start with iron or steel scrap,.such as borings, lpunchings, cuttings, cli pings and the like, with the parts preferalbly in l fairly small form, and cleaned, if necessary,

to remove foreign substances. In the event the scrap is of fairly large size, it can be chopped into pieces of suitable small size.'

I prefer to start with scrap iron or steel, as just'stated,ffor the reason that I nd that I can in this manner obtain Ymaterial which for all practical purposes is free 0f Application filed December 6, 1920. 4Serial No. 428,583.

impurities." At any rate, this material is exceedin ly more free of impurities than the besti avallable grade of ore such as iron 0X1 e.

As the first chief step of my improvedv process, assuming that clean scrap material of the right size is obtained, I convert the material to an oxide of iron in a powderous form. This is preferably. done in apparatus such as shown in the drawings, namely, in a heated tumbling container through which a suitable oxidizing medium is passed. This same apparatus can be used to advantage also in carrying out the subsequent steps of the process I will there- .fore briefly refer to the drawing, iii which Figs. l and 2 are longitudinal and transverse vertical sections, respectively, showing apparatus which may be used in carrying out the process.

The apparatus shown in the drawing vincludes an outer heating chamberrlO carrying an inner revolubleJ container 11, rotatably supported through the medium of hollow shafts or trunnions 12 in opposite walls of the chamber 10. The inner chamber 1l may be rotated by any suitable means, such as indicated at 13. The outer chamber is preferably provided with suit-able orifices or pipes 14 for the supply of. heating gases or. flames whichcan be directed as desired, or the chamber 10 can be otherwise heated. The chamber 11 is preferably formed of a suitable non-oxidizing material such as nickel.

It is in the inner chamber 11 that the steps of the process are carried out, i. e. the oxidizing step, the subsequent reducing step, and the carbonizing step if steel is produced, the gases for accomplishing these results beingpreferably admitted and withdrawn from the chamber 11 through the trunnions. In this instance gas supply pipes 15 are shown for supplying the gasesfor these purposes.

The material which is first'to be oxidized, is supplied to the chamber'll, which will be provided with a suitable man-hole for this purpose, and when the chamber is heated to the right temperature, which may be varied, but preferably about 1400o to 1600 Fahrenheit, the oxidizing gas or medium is passed through the chamber while it is undergoing a continuous rotation. For the oxidizing medium I prefer tol use steam, though any othersuitable gas may be employed. While the material is subjected to the oxidizing medium in the rotating container 11, it is thoroughly agitated for the double purpose of permitting the proper and uniform access of the oxidizing medium to the material, but 'chiefly for the purpose of knocking ofi or freeing from the 'particles or pieces being oxidized, the oxide as fast as it is formed, so that there will be constantly presented to the oxidizing medium fresh metal to be oxidized. For this purpose the container is preferably provided on the interior with inwardly extending flanges or ribs indicated at 16 so as to carry the material being treated part way around, and permit it to drop to t e bottom of the container through the body of steam or other oxidizing mediumemployed. Tf the oxidizing of the metal and the breaking ofi' or clearing of the oxide from the metal should not be carried out rapidly enough by the mere act of tumbling the pieces being treated, T contemplate inserting in the chamber non-oxidizable balls or equivalent material which is tumbled or rolled around with the material being oxidized so as to accelerate this action.

If steam is used as the oxidizing agent, hydrogen is given off and can be conveyed to a suitable gasometer for use in a subse quent step of the process.

This oxidizing step will be carried on until the material being treated is converted to a fine powderous oxide. The time to discontinue the oxidizing step can be determined either by testing the material beingoxidized, or by testingthe gas which leaves the container. Tf the last mentioned test shows absence of hydrogen, the oxidation is complete.

Then after the oxide is obtained in the form of a fine powder as above explained, as a second step the oxide is converted to a fine and practically pure metallic iron preferably by reducing the oxide while still in the container 11. Any suitable reducing gas may be employed, such as hydrogen, water gas or carbon monoxide, and inthe event that steam was utilized for the oxidizing step, the hydrogen given off and eollected in the gasometer will be passed through the chamber to convert the oxide, or to assist in converting the oxide to the metallic iron.

After the reducing step is completed, the fine and practically pure metallic iron is allowed to cool, preferably in the presence of the reducing gas, so as to prevent entirely any oxidation while the temperature is being reduced to the working temperature for the subsequent steps of the process.

From this point the process will be varied, depending upon whether the ultimate'product is iron or steel, and it might be mentioned at this point that if an alloy is to be produced, the above process will be -varied somewhat, as will be explained subsequently. Assuming, however, that an iron roduct is to be obtained, the fine metallic iron is with a suitable press and suitably shaped mold, compressed under very high pressure into a solid body. In this step of the process T can produce finished smooth lsurfaced articles or products of the desired size and shape with a reater degree of accuracy than is genera ly possible when the articles are cast and'then machined. However, after the compressing step, the articles are preferably heated or sintered, and it is chararteristic of the sintering that the article undergoes noshrinkage, at least it undergoes no shrinkage of any conseuence, this being due to the fact that pure, nely divided iron, free of oxides, silicon and the like is compressed in the mold.

Tn the event that the iron is not to be compressed into smooth surfaced finished articles of given size, the iron can be molded into bricks or ingots which can be heated and forged, 'and subsequently worked into any desired' shape. 1

llf steel is to be formed, the process is the same as that above described, as far as the oxidizing and reducing steps are concerned, and after the nely divided metallic iron is obtained, a carbonizing gas such as carbon monoxide is supplied to, or passed through the' chamber 11 while the finely divided iron is being agitated bythe rotation of the chamber at the desired temperature such as 14000 to 1600o Fahrenheit, or higher if desired, and this is continued until the :iron is carbonized to the right degree, producing finely divided steel. With this process the exact amount of carbonizing is ob'- tained, or a definite carbon content can be gotten into the steel either by supplying a predetermined amount of the carbonizing gas necessary to impart the desired carbon content, or this can be determined by extracting samples from time to time, which can be tested, and the carbonizing step continued until the tests show that steel is btained 'having the desired carbon content. Thereupon the supply of carbonizing gas Ilis discontinued, and the finely divided steel is allowed to cool, the cooling taking place under conditions which prevent oxidation.

From this point the process can be com- 'pleted as in the production of iron, namely,

the finely divided or powdered steel is compacted or4 compressed under very severe pressure either to the shape and size that the final article is to assume, or it can be compressed into a bar or block to be subsequently worked, the same as with an ordinary cast ingot, in which event it is heated to a welding heat, and then preferably forged in a suitable press or hammer into a perfectly solid, physically homogeneous to the chamber 11 at the beginning of' the.

process, or at some other desired point of the process, and I may supply the metal or.

metals themselves, or compounds of the metals, such as oxides, the right amount being added in each instance to obtain the desired. content of the alloying metal or metals. The alloying metal or metals, whether 1n a pure metallic state, or in thepform of compounds, such as oxides, are preferably added to the chamber 11 with the iron or steel scrap, the process being otherwise the same as that utilized for the production of steel.

Whether the -alloying metal or metals are supplied in a metallic state or in the form of oxides, in the reducing step the oxide or.

oxides will be reduced along with the iron oxide to the metallic state, and after the carbonizing step there is practically a perfect and uniform mixture of finely divided steel and the metal or metals to be alloyed therewith. However, with alloying metals which can not be reduced as readily as oxide of iron, the' finely divided metal or metals will be added after the reducing step, to the finely divided metallic iron. and thoroughly mixed therewith, after which the carbonizing step is carried out as in the production of steel, or the mixing can be conducted after the carbonizing step.

The process is then continued precisely 'as explained in connection with the produc. tion of steel. That is to say, the thoroughly mixed metals are compressed in a press under suitable severe pressure to form a dense bar or ingot which is subsequently heated to welding temperature and then forged to produce the alloying and for the purpose of working the bar or ingot into the desired shape, or the mixed metals can be molded into the desired shape of the finished article in a press-capable of subjecting the materials to a sufiiciently high pressure and then the alloying can be accomplished by heating the molded articles andallowing them to cool either gradually or suddenly, as by quenching them if they are to be tempered. In thus alloying the compressed articles the molded article whether or not in the form of a bar, is heated to a point which does not exceed the meltingr temperature of the least refractory metal. y

It will be seen therefore,that by the above process I am enabled to produce iron, steel, or steel alloy, whether or not in the shape of the final article to be produced, with the steel having the precise or exact carbon content desired, and with the alloy having the desired metal content, and this is accomplished without any melting A of smelting" process. Furthermore, the article is homogeneous chemically and physically, especially when it is forged int'o an absolutely nonporous body,vand as the product is 'absolutely free from such imperfections as blow-holes, common in casting, as there is a complete absence of so-called segregations, a high grade product is obtained.

I might say in conclusion, that any of the y usual steel alloys can beproduced, the process being very well adapted for .the production of alloys from iron and any of the metals which alloy therewith, such as tungsten, nickel, cobalt, molybdenum, etc.

'Above I have described the preferred way of carrying out the process for the production of iron, steel, or steel alloys, including the several steps which can be carried out in sequence when starting with iron and steel scrap, but I wish it to ,be understood that I am not to be limited to the combination of steps herein recited, as one or more of them may be used advantageously without others. Having described my invention, I claim: l. The process which comprises oxidizing iron or steel scrap so as to vproduce iron oxide in finely divided form, reducing the oxide 3. The steps in the process of producing I iron or steel bodies which comprise agitating iron or steel scrap in a heated container in the presence of an oxidizing medium so as to produce iron oxide in finely divided form, and subsequently subjecting the oxide to the ,action of a reducing gas so as to produce finely divided metallic iron.

4. The steps in the process of producing iron or steel bodies which comprise agitating iron or steel scrap in a heated container in the presence of an oxidizing medium so as to produce iron oxide in finely divided form, subjecting the oxide to the action of a reducing gas so as to produce finely divided metallic iron, and subsequently compressing the finely divided material into a solid body.

5. The step in the process of making steel which comprises subjecting metallic iron in finely divided form to the action of a carbonizinggas. y

6.. The step in the process of making steelI whlch comprises agitating finely divided( metallic iron in a heated container in the presence of a carbonizin gas.

7. The process of maklng steel which comprises converting iron or steel scrap tol oxide of iron, treating tlns so as to produce finelyy dlvlded metallic iron, and carbonizing the finely divided iron by subjecting. it at a suitable temperature to a carbonizing,F gas producing finelyl divided steelof the desired carbon content. I

8. The process of making steel which comv prises converting iron or steel scrap to oxide off during the oxidizing step through the,

container so as to reduce the oxide to finely divided metallic iron.

l0. The. process of making steel which comprises treating iron or steel scrap so as to produce oxide of iron, reducing'the oxide of iron to metallic iron in finely divided state, subjecting the metallic iron to the action of a carbonizing gas until carbonized the desired amount, and forming by compression a solid body from the product thus obtained.

l1. rl`he process of making alloys which comprises treating iron or steel scrap lwith an oxidizing,l medium so as to produce iron oxide, reducing,- the oxide to metallic iron in powdered form, carloonizingr the metallic iron, adding the desired am'ount of the alloying metal or metals or compounds there' of at a suitable. point in the process so as to obtain a uniform mixture of finely di- 4 vided steel and of the metal or metals to be alloyed therewith, and subsequently subjecting the mixture to severe pressure so as to produce a solid body.

l2. The process of making alloys which comprises treating iron or steel scrap with an oxidizin medium so as to produce iron oxide, reducing the oxide to metallic iron in powdered form, carbonizing the metallic iron, adding the desired amount of the all'oying metal or metals or compounds thereof at a suitable point in the process so as to obtain a uniform mixture of Vnely divided steel and of the metal or metals to be. alloyed therewith, subsequently subjecting the mixture to'severevpressureso as to produce a solid body, and heating it to a point below the melting; temperature of the' least refractory metal.

13. rhe process which comprises converting iron or steel scrap into finely divided iron oxide, treating the oxide so as to convert it to powdered metallic iron, subsequently treating the metallic iron so as to produce a solid metallic body, and heating; it.

14C. rllhe process which comprises oxidizing iron or steel scrap, treating the same so as to produce finely divided iron oxide, subjecting the oxide to the action of a reducing medium under heat conditions which will convert the oxide to finely divided metallic iron, and producing a solid body by com pression and subseouent heating.

lln testimony whereof, ll hereunto aiiix my signature.

JUSEPH A. WILLIAMS. 

